Suggested changes to python learning exercise

Hello everybody :wave:
During the course of the evaluations of the python exercise “isogram”, it experienced a strange behavior of the test_empty_string(self) function.

Since an isogram “…is a word or phrase without a repeating letter…”, in my program, I first checked if the variable string was empty and returned False if it was empty. An empty string shouldn’t be neither a word nor an isogram[1].

I searched for pull requests in the repository and previous related posts in the forum (test_empty_string #exercism:bugs-and-features), but I haven’t found any.

These are the proposed changes:

diff --git a/exercises/practice/isogram/ b/exercises/practice/isogram/
index c65984f6..80c47839 100644
--- a/exercises/practice/isogram/
+++ b/exercises/practice/isogram/
@@ -11,7 +11,7 @@ from isogram import (
 class IsogramTest(unittest.TestCase):
     def test_empty_string(self):
-        self.assertIs(is_isogram(""), True)
+        self.assertIs(is_isogram(""), False)
     def test_isogram_with_only_lower_case_characters(self):
         self.assertIs(is_isogram("isogram"), True)

I didn’t create a pull request (as instructed in guidelines), but I am ready to create it, since the proposed changes have been already pushed into another branch.

Thank you for your help and sorry for the inconvenience. Please excuse me if I am wrong.

Please let me know if there is anything else I might do.

[1] wiktionary entry on isogram: A word or phrase in which each letter occurs the same number of times.

You may want to read Suggesting Exercise Improvements | Exercism's Docs

There are multiple reasons in that doc that suggest this PR is likely not a good fit.

Thank you, @IsaacG. I followed your suggestion. :grinning:
I did not take into account some of the consequences.

I hope this message would serve as reference to other users if they ever experience similar difficulties with in that exercise. :smile:

Thank you for your patience.